I talked to Debra Smith from MSP (517-322-5548) regarding this issue.
According to her, a license to purchase (aka purchase permit) IS required for all pistols (unless it is exempt: made on/before 1898) even if you have a C&R license.
So for instance, you want a CZ-52 and you have a C&R license.
You must first obtain the license to purchase and mail it to the seller/vendor along with a copy of your C&R and have them fill out the rest and mail it back to you along with the pistol. Then you'd get the pistol registered as usual.
Now here's the interesting question:
What happens if I don't bother with the purchase permit? Well, according to Debra, the registering agency (aka CLEO) may confiscate the pistol because it was obtained "illegally" under Michigan law, or they may require you to fill out the permit on the spot.
My CLEO now charges $5 for purchase permits. Registration is still "free"